1. Field of the Invention
This invention pertains generally to the measurement of ultraviolet (UV) radiation and, more particularly, to a system and method for monitoring the exposure of a workpiece to UV radiation during a curing process.
2. Description of the Prior Art
In one type of UV curing system, which is sometimes referred to as a UV curing conveyor, a workpiece is passed on a conveyor beneath a UV source to effect a photochemical change in the workpiece. The exposure of the workpiece to the UV radiation should be carefully monitored because too little exposure will not permit the curing process to be completed, and too much exposure is wasteful and reduces the number of parts which can be processed in a given time.
Since heat is usually a byproduct of the curing process, instruments employed to monitor the UV exposure are often subjected to high temperatures which can affect their performance. Another problem with devices heretofore provided for monitoring UV exposure is that they are not able to provide accurate measurements over a broad range of temperatures.
One device heretofore provided for measuring UV radiation is described in U.S. Pat. No. 4,644,165. That device is self contained and is intended primarily for use in determining the total amount of UV energy applied to photoetch material in the manufacture of printed circuit boards.